Laurent,
The item that distinguishes a "Boss" 302 engine from its 302 Windsor brethren are its canted-valve Cleveland cylinder heads. The heads you are using on your 302 engine are not Cleveland cylinder heads, it is therefore mis-leading to refer to it as a "Boss" 302. The block may very well be sourced from a "Boss" 302, but the cylindr head distinction is an important one. The valve reliefs in the pistons, the connecting rod lengths & the piston's wrist pin height are totally different between the Boss 302 & 302 Windsor motors.
On the subject of camshafts: a camshaft custom ground by someone who understands the peculiarities of your engine will always perform better than a generic off-the-shelf camshaft. I have no contacts to recommend in France. My best recommendation in the US is Mark McKeown of MME Racing, telephone (301) 246-9225.
Website: http://www.mmeracing.com
Be prepared to answer alot of questions about your car.
Good luck, best wishes & Happy New Year.
George
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.